I thought replacing the motor on my port windshield wiper would be a fairly simple job. Think again. I've learned that I need to remove the wiper arm off of the motor. I bought an automotive "wiper arm puller" tool. But alas, the hardtop only gives me a couple of inches to work with and I can't use the tool. Creative ideas for getting that off? And, thinking ahead, how will I press the arm back onto the new motor?

If your tossing the old motor, use a sawzall with metal cutting blade.
Put a towel around near etc... it to catch the metal bits.
Then you can remove the leftovers from the arm.
New blade on new motor is a slip type fit. Use anti seize or marine grease to keep it from seizing.

Is there a nut holding it on?
You could try a pry bar, maybe one on each side and some spray rust buster and a block of wood against the FG. But the saw is easy, and prying might crack the gel coat.

If your tossing the old motor, use a sawzall with metal cutting blade.
Put a towel around near etc... it to catch the metal bits.
Then you can remove the leftovers from the arm.
New blade on new motor is a slip type fit. Use anti seize or marine grease to keep it from seizing.

Is there a nut holding it on?
You could try a pry bar, maybe one on each side and some spray rust buster and a block of wood against the FG. But the saw is easy, and prying might crack the gel coat.

Thanks for the direction. I was trying to be more surgical about it and don't think about bringing my sawzall aboard too often. (Second favorite tool next to the Sonicrafter!). Anyhow, yes there was a nut on the outside, when loosened allowed me to pull the motor on the inside away from the fiberglass, enough to cut the shaft and remove the motor.

Back on the workbench at home, I discovered a tiny set screw in the shaft where it connects to the wiper arm. Backed that off and a couple of taps with a nail set drove the pin out of the arm. I expected to find a part # on the inside, but NO, that would be too simple. They show a multitude of models on the Marinco web site. The shaft size 1.5" or 2.5" is the primary factory. Besides that all of the other options are for the preset sweep angle, which can be adjusted on any of them to a wide range. $180 part is on its way. Probably would have been a $500 bill had I let the marina guys do this for me.

I just took one of ours off before lunch. I applied enough force after seeing how the latch worked to hold the arm on, but without success. Zinc or aluminum corroded in contact with the brass stem. I sacrificed the arm to save the motor. I cut a slice in the arm's bracket with the intention of not damaging the stem. I used a broken-off hacksaw blade mounted in a plastic handle; my Dremel is at home. Then broke the bracket. The rest was easy.

The motor would not turn until I disassembled the gearbox. The problem is that the stem is not lubricated and is made so that not much water can get into it. I hotwired the motor to run it and it's fine. The grease in the gearbox is quite hard and dry. I have it working now, but will take it home to clean and lubricate.

Need to buy a new wiper arm; looks like ordinary automotive stuff from the 80's and back. I'll buy two on the theory that I might as well do the other one, too.

I may have to buy new arms also. I like my old SS arms. I don't like the idea of them being special boat wipers with a commensurate price.
One advantage, they have a screw you can adjust the angle position of the blade.

I actually dont need wipers at all. The boat goes so slow it is not like a car windshield. Plus you can use Rain-X. And it does not rain that much and when it does mostly a light rain.

A car going fast, you need wipers it does help. But even Rain-X works well in cars.

Typical of much of the 80's designed accessories on my boat. If they knew how long we would keep the boat, they would have come up with a better, more durable and less corrosion prone design.
I had to remove one of my 3 motors when I let the smoke out of it several years (15?) ago. Like most electronics, those motors don't run without the smoke. I had some corrosion holding the blades on, but I was able to pry them off. Now my blades need replacement and I dread the search.